Jam freeing agent for drilling fluid as well as preparation and application of jam freeing agent

Abstract

The invention discloses a jam freeing agent for drilling fluid. The jam freeing agent comprises the following components: 35-48 parts of a penetrant, 5-12 parts of a stabilizer, 6-15 parts of a flow pattern regulator, 25-35 parts of an emulsifier and 2-10 parts of base oil. The invention also discloses a preparation method and application thereof. According to the jam freeing agent for the drilling fluid, on the basis that the jam freeing effect is guaranteed, the temperature resistance of a product is improved, and hard sinking is avoided. The jam freeing agent for the drilling fluid, provided by the invention, is good in rheological property under high-temperature and high-density conditions, and adapts to the on-site high-temperature and high-density jam freeing agent emulsion preparation requirements.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oilfield drilling fluid, and particularly relates to a drilling fluid releasing agent and a preparation and application thereof. BACKGROUND

[0002] In recent years, with the gradual exploration and development of deep wells and ultra-deep wells, the drilling fluid density and the bottom hole temperature gradually increase. Once sticking occurs in deep wells, the releasing agent is the first choice for releasing. The existing releasing agent has the following two problems under the conditions of deep wells, ultra-deep wells, high temperature and high density: ① limited temperature resistance, serious sedimentation problem; ② poor rheological performance under high density conditions. In order to solve these problems, it is necessary to improve the temperature resistance of the releasing agent and avoid hard sedimentation. Under the conditions of high temperature and high density, the performance of the releasing agent is optimized to adapt to the configuration requirements of the releasing agent emulsion on site.

[0003] CN101838524A discloses an oil-soluble releasing agent for drilling fluid. The releasing agent is composed of the following components by weight percentage: emulsified asphalt powder 30-40%, diesel oil 50-60%, surfactant 1-5%, penetrating agent 1-5%, gel breaker 0.1-0.2%, and demulsifier 0.05-0.1%. The releasing agent prepared by the present application has a density of 0.9-2.5 g / cm 3 , can resist temperature of 150℃, and has simple process. However, the releasing agent has limited effect under the condition of high bottom hole temperature.

[0004] CN106590561A discloses a palm oil-based releasing agent and a preparation method thereof. The weight percentage of each component of the releasing agent is as follows: organic clay 4-6 parts, fluid loss additive 0-4 parts, emulsifier 4-5 parts, rapid penetrating agent 1-3 parts, oleic acid 1-3 parts, base oil 60-90 parts, and water phase 0-30 parts. The releasing agent has excellent releasing performance and high releasing efficiency. However, the density of the releasing agent prepared by the present application is more than 2.0 g / cm 3 , and the rheological performance is poor after flowing, which is not suitable for the configuration requirements of the releasing agent emulsion on site.

[0005] CN107312512A discloses an oil-based releasing agent. The releasing agent includes the following raw materials by weight percentage: 60-70 parts of base oil, 7-10 parts of penetrating agent, 4-6 parts of modified organic clay, 3-7 parts of additive, 2-5 parts of 1.0 mol / L sodium chloride solution, and 1-3 parts of methyl pyrrolidone. The oil-based releasing agent prepared by the present application greatly shortens the releasing time, but the preparation method is relatively complex, and the effect is limited under the condition of high bottom hole temperature.

[0006] In view of the problems of the existing art, such as complex preparation, limited temperature resistance, poor rheological performance under high density conditions, and the like, it is an urgent problem for those skilled in the art to develop a releasing agent with simple preparation process, excellent temperature resistance, and wide density range of emulsion. SUMMARY

[0007] In order to further increase the selection space of the releasing agent for drilling fluid, the present application is made.

[0008] As an aspect of the present application, a releasing agent for drilling fluid is provided, which comprises, by weight fraction, the following components: 35-48 parts of a penetrating agent, 5-12 parts of a stabilizer, 6-15 parts of a flow pattern modifier, 25-35 parts of an emulsifier, and 2-10 parts of base oil. As a preferred embodiment, the amount of the penetrating agent is 35-45 parts. As a further preferred embodiment, the amount of the stabilizer is 5-10 parts.

[0009] In specific embodiments, the penetrating agent is one or both of isooctyl alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether sodium sulfate.

[0010] In specific embodiments, the stabilizer is diesel-based organic soil (Tianjin Jin Haopeng Business and Trade Co., Ltd.).

[0011] In specific embodiments, the flow pattern modifier is one or both of dodecyl trimethyl ammonium chloride and di-light ethyl lauric amine.

[0012] In specific embodiments, the emulsifier is one or both of polyacrylic acid sodium and dodecyl sodium sulfate.

[0013] In specific embodiments, the base oil is one or both of 0# diesel oil (Huaoyou Supply Place Beizhan Road Gas Station) and 5# white oil (Shandong Lifeng Chemical Co., Ltd.).

[0014] As another aspect of the present application, a method for preparing the releasing agent for drilling fluid is provided, which comprises:

[0015] (1) mixing the penetrating agent with the stabilizer;

[0016] (2) adding the flow pattern modifier and mixing;

[0017] (3) adding the emulsifier and mixing;

[0018] (4) adding the base oil and mixing.

[0019] As a further aspect of the present application, the releasing agent for drilling fluid is applied in oil and gas drilling.

[0020] The drilling fluid releasing agent provided by the present application has a temperature resistance of up to 180 DEG C, and has the following advantages compared with similar releasing agents.

[0021] (1) The drilling fluid releasing agent provided by the present application has improved temperature resistance and avoids hard precipitation while ensuring releasing effect.

[0022] (2) The drilling fluid releasing agent provided by the present application can be used to prepare a releasing agent emulsion with a density ranging from 1.04 g / cm 3 ~ 2.16 g / cm 3 , and has a wide density range. The releasing agent emulsion has good rheological properties under high-density conditions, and meets the requirements of high-temperature and high-density releasing agent emulsion on site. DETAILED DESCRIPTION

[0023] The present application is described in detail below by citing examples, and it should be noted that the examples are only used to further illustrate the present application, and cannot be understood as limiting the protection scope of the present application. Some non-essential improvements and adjustments made to the present application still fall within the protection scope of the present application.

[0024] The part referred to in the present application is mass part.

[0025] Example 1 (formula example)

[0026] The drilling fluid releasing agent I has the following components:

[0027] 35 parts of isooctanol polyoxyethylene ether, 5 parts of diesel-based organic soil (Tianjin Jin Haopeng Business and Trade Co., Ltd.), 6 parts of dodecyltrimethylammonium chloride, 25 parts of sodium dodecyl sulfate, and 2 parts of No. 0 diesel oil (North Station Gas Station of Huayou Supply Place).

[0028] The preparation method of the drilling fluid releasing agent I is as follows:

[0029] (1) 35 parts of isooctanol polyoxyethylene ether are taken in a slurry cup, 5 parts of diesel-based organic soil (Tianjin Jin Haopeng Business and Trade Co., Ltd.) are added under the condition of 11000 r / min, and high-speed stirring is continued for 5 minutes for mixing;

[0030] (2) 6 parts of dodecyltrimethylammonium chloride are added under the condition of 11000 r / min, and high-speed stirring is continued for 5 minutes for mixing;

[0031] (3) 25 parts of sodium dodecyl sulfate are added under the condition of 11000 r / min, and high-speed stirring is continued for 5 minutes for mixing;

[0032] (4) 2 parts of No. 0 diesel oil (North Station Gas Station of Huayou Supply Place) are added under the condition of 11000 r / min, and high-speed stirring is continued for 20 minutes for mixing, and a composition is obtained.

[0033] The obtained composition is a releasing agent for drilling fluid.

[0034] Example 2 (formulation example)

[0035] The releasing agent II for drilling fluid has the following components:

[0036] 45 parts of sodium fatty alcohol polyoxyethylene ether sulfate, 10 parts of diesel-based organic soil (Tianjin Jin Haopeng Business and Trade Co., Ltd.), 15 parts of one-two light ethyl lauric phthalamide, 35 parts of sodium polyacrylate, and 5 parts of No. 5 white oil (Shandong Lifeng Chemical Co., Ltd.).

[0037] The preparation method of the releasing agent II for drilling fluid is as follows:

[0038] (1) Take 45 parts of sodium fatty alcohol polyoxyethylene ether sulfate in a slurry cup, add 10 parts of diesel-based organic soil (Tianjin Jin Haopeng Business and Trade Co., Ltd.) under the condition of 11000 r / min, continue to stir at high speed for 10 minutes, and mix;

[0039] (2) Add 15 parts of one-two light ethyl lauric phthalamide under the condition of 11000 r / min, continue to stir at high speed for 10 minutes, and mix;

[0040] (3) Add 35 parts of sodium polyacrylate under the condition of 11000 r / min, continue to stir at high speed for 10 minutes, and mix;

[0041] (4) Add 5 parts of No. 5 white oil (Shandong Lifeng Chemical Co., Ltd.) under the condition of 11000 r / min, continue to stir at high speed for 30 minutes, and mix to obtain the composition.

[0042] The obtained composition is a releasing agent for drilling fluid.

[0043] Example 3 (formulation example)

[0044] The releasing agent III for drilling fluid has the following components:

[0045] 21 parts of isooctanol polyoxyethylene ether, 21 parts of sodium fatty alcohol polyoxyethylene ether sulfate, 8 parts of diesel-based organic soil (Tianjin Jin Haopeng Business and Trade Co., Ltd.), 5 parts of dodecyltrimethylammonium chloride, 5 parts of one-two light ethyl lauric phthalamide, 15 parts of sodium polyacrylate, 15 parts of sodium dodecyl sulfate, 5 parts of No. 0 diesel oil (Huayou Supply Place North Station Road Gas Station), and 5 parts of No. 5 white oil (Shandong Lifeng Chemical Co., Ltd.).

[0046] The preparation method of the releasing agent III for drilling fluid is as follows:

[0047] (1) Take 21 parts of isooctanol polyoxyethylene ether, 21 parts of fatty alcohol polyoxyethylene ether sodium sulfate in a slurry cup, add 8 parts of diesel-based organoclay (Tianjin Jin Haopeng Business and Trade Co., Ltd.) under the condition of 11000 r / min, continue to stir at high speed for 8 minutes, mix;

[0048] (2) Add 5 parts of dodecyl trimethyl ammonium chloride, 5 parts of lauryl ethylamine under the condition of 11000 r / min, continue to stir at high speed for 8 minutes, mix;

[0049] (3) Add 15 parts of sodium polyacrylate, 15 parts of sodium dodecyl sulfate under the condition of 11000 r / min, continue to stir at high speed for 8 minutes, mix;

[0050] (4) Add 5 parts of No. 0 diesel oil (Huayou Supply Place North Station Road Gas Station), 5 parts of No. 5 white oil (Shandong Lifeng Chemical Co., Ltd.) under the condition of 11000 r / min, continue to stir at high speed for 25 minutes, mix, to obtain a composition.

[0051] The obtained composition is a drilling fluid release agent.

[0052] Example 4 (formula example)

[0053] The drilling fluid release agent IV has the following components:

[0054] Isooctanol polyoxyethylene ether 30 parts, fatty alcohol polyoxyethylene ether sodium sulfate 10 parts, diesel-based organoclay (Tianjin Jin Haopeng Business and Trade Co., Ltd.) 12 parts, lauryl ethylamine 12 parts, sodium polyacrylate 32 parts, No. 0 diesel oil (Huayou Supply Place North Station Road Gas Station) 8 parts.

[0055] The preparation method of the drilling fluid release agent IV is as follows:

[0056] (1) Take 30 parts of isooctanol polyoxyethylene ether, 10 parts of fatty alcohol polyoxyethylene ether sodium sulfate in a slurry cup, add 12 parts of diesel-based organoclay (Tianjin Jin Haopeng Business and Trade Co., Ltd.) under the condition of 11000 r / min, continue to stir at high speed for 6 minutes, mix;

[0057] (2) Add 12 parts of lauryl ethylamine under the condition of 11000 r / min, continue to stir at high speed for 6 minutes, mix;

[0058] (3) Add 32 parts of sodium polyacrylate under the condition of 11000 r / min, continue to stir at high speed for 6 minutes, mix;

[0059] (4) Add 8 parts of No. 0 diesel oil (Huayou Supply Place North Station Road Gas Station) under the condition of 11000 r / min, continue to stir at high speed for 22 minutes, mix, to obtain a composition.

[0060] The obtained composition is a releasing agent for drilling fluid.

[0061] Example 5 (formulation example)

[0062] The releasing agent V for drilling fluid has the following components:

[0063] Sodium fatty alcohol polyoxyethylene ether sulfate 48 parts, diesel-based organoclay (Tianjin Jin Haopeng Business and Trade Co., Ltd.) 11 parts, dodecyl trimethyl ammonium chloride 10 parts, lauryl dimethylamine oxide 3 parts, sodium polyacrylate 10 parts, sodium dodecyl sulfate 20 parts, No. 5 white oil (Shandong Lifeng Chemical Co., Ltd.) 6 parts.

[0064] The preparation method of the releasing agent V for drilling fluid is as follows:

[0065] (1) Take 48 parts of sodium fatty alcohol polyoxyethylene ether sulfate in a slurry cup, add 11 parts of diesel-based organoclay (Tianjin Jin Haopeng Business and Trade Co., Ltd.) under the condition of 11000 r / min, continue to stir at high speed for 7 minutes, and mix;

[0066] (2) Add 10 parts of dodecyl trimethyl ammonium chloride and 3 parts of lauryl dimethylamine oxide under the condition of 11000 r / min, continue to stir at high speed for 7 minutes, and mix;

[0067] (3) Add 10 parts of sodium polyacrylate and 20 parts of sodium dodecyl sulfate under the condition of 11000 r / min, continue to stir at high speed for 7 minutes, and mix;

[0068] (4) Add 6 parts of No. 5 white oil (Shandong Lifeng Chemical Co., Ltd.) under the condition of 11000 r / min, continue to stir at high speed for 28 minutes, and mix to obtain the composition.

[0069] The obtained composition is a releasing agent for drilling fluid.

[0070] Comparative Example 1 (formulation example)

[0071] The releasing agent VI for drilling fluid has the following components:

[0072] Sodium fatty alcohol polyoxyethylene ether sulfate 32 parts, diesel-based organoclay (Tianjin Jin Haopeng Business and Trade Co., Ltd.) 3 parts, dodecyl trimethyl ammonium chloride 4 parts, sodium polyacrylate 22 parts, No. 0 diesel oil (Huayou Supply Office North Station Road Gas Station) 1 part.

[0073] The preparation method of the releasing agent VI for drilling fluid is as follows:

[0074] (1) Take 32 parts of sodium fatty alcohol polyoxyethylene ether sulfate in a slurry cup, add 3 parts of diesel-based organoclay (Tianjin Jin Haopeng Business and Trade Co., Ltd.) under the condition of 11000 r / min, continue to stir at high speed for 3 minutes, and mix;

[0075] (2) Add 4 parts of dodecyltrimethylammonium chloride at 11000r / min and continue stirring at high speed for 3 minutes to mix;

[0076] (3) Add 22 parts of sodium polyacrylate at 11000r / min and continue stirring at high speed for 3 minutes to mix;

[0077] (4) Add 1 part of No. 0 diesel (Huayou Supply Department Beizhan Road Gas Station) at 11000r / min, continue high-speed stirring for 15 minutes, mix, and obtain the composition.

[0078] The resulting composition is an unblocking agent for drilling fluids.

[0079] Comparative Example 2 (Formulation Example)

[0080] Drilling fluid unblocking agent VII has the following components:

[0081] 50 parts of isooctanol polyoxyethylene ether, 15 parts of diesel-based organic clay (Tianjin Jinhaopeng Trading Co., Ltd.), 17 parts of dihydroxyethyl lauryl phthalide, 38 parts of sodium dodecyl sulfate, and 15 parts of No. 5 white oil (Shandong Lifeng Chemical Co., Ltd.).

[0082] The preparation method of the drilling fluid unblocking agent VII is as follows:

[0083] (1) Take 50 parts of isooctanol polyoxyethylene ether into a slurry cup, add 15 parts of diesel-based organic clay (Tianjin Jinhaopeng Trading Co., Ltd.) at 11000r / min, and continue to stir at high speed for 15 minutes to mix;

[0084] (2) Add 17 parts of dihydroxyethyl laurylamine at 11000 r / min and continue stirring at high speed for 15 minutes to mix;

[0085] (3) Add 38 parts of sodium dodecyl sulfate at 11000 r / min and continue stirring at high speed for 15 minutes to mix;

[0086] (4) Add 15 parts of No. 5 white oil (Shandong Lifeng Chemical Co., Ltd.) at 11000r / min, continue high-speed stirring for 35 minutes, mix, and obtain the composition.

[0087] The resulting composition is an unblocking agent for drilling fluids.

[0088] Performance Evaluation 1 (Rheological Properties of the Unblocking Agent Emulsion)

[0089] The rheological properties of the unblocking agent emulsion were tested. The test method was as follows: Two stainless steel high-speed stirring cups were used. 233 mL of No. 0 diesel oil (from the Beizhan Road Gas Station of Huayou Supply Department) was measured using a graduated cylinder and added to each cup. 6 g of diesel-based organic clay (from Tianjin Jinhaopeng Trading Co., Ltd.) was added at 11000 rpm, and stirring was continued for 5 minutes. Then, 40 mL of drilling fluid unblocking agent was added at 11000 rpm, and stirring was continued for 5 minutes. Next, 127 mL of distilled water was added at 11000 rpm, and stirring was continued for 10 minutes. Finally, 140 g of barite powder (from Sichuan Haiwo Petroleum Engineering Technology Co., Ltd.) was added at 11000 rpm, and stirring was continued for 20 minutes. The resulting two liquids were the unblocking agent emulsions, and their rheological properties were tested separately. One emulsion was tested at 50℃, and the other was aged and then tested at 50℃. The aging conditions were 180℃ × 16 h.

[0090] The rheological properties of the unblocking agent emulsions prepared in Examples 1-5 and Comparative Examples 1-2 were tested respectively, and the test results are shown in Table 1 below.

[0091] Table 1:

[0092]

[0093]

[0094] As can be seen from the test results in Table 1, the unblocking agent emulsions prepared in Examples 1-5 of this invention exhibit good rheological properties before and after aging at 180℃ for 16 hours. In contrast, the unblocking agent emulsions prepared in Comparative Examples 1-2 show poor rheological properties and significant oil-water separation after aging at 180℃ for 16 hours, with the emulsion at the bottom of the aging tank exhibiting a tofu-like appearance.

[0095] Performance Evaluation 2 (Thermal Stability of Unblocking Agent Emulsion)

[0096] The thermal stability of the unblocking agent emulsion was tested. The test method was as follows: Take a stainless steel high-speed stirring cup, measure 233 mL of No. 0 diesel oil (from the Beizhan Road Gas Station of Huayou Supply Department) using a graduated cylinder, and add it to the stainless steel high-speed stirring cup. Add 6 g of diesel-based organic clay (Tianjin Jinhaopeng Trading Co., Ltd.) at 11000 r / min, and continue stirring for 5 minutes. Add 40 mL of drilling fluid unblocking agent at 11000 r / min, and continue stirring for 5 minutes. Add 127 mL of distilled water at 11000 r / min, and continue stirring for 10 minutes. Add 140 g of barite powder (Sichuan Haiwo Petroleum Engineering Technology Co., Ltd.) at 11000 r / min, and continue stirring for 20 minutes. The resulting liquid is the unblocking agent emulsion. Pour this unblocking agent emulsion into a stainless steel aging tank. After purging the stainless steel aging tank with nitrogen gas for 30 seconds at 690 kPa pressure, place it vertically in an electric drying oven at 180℃ and let it stand at a constant temperature for 16 hours. Keeping the container vertical, remove the stainless steel aging tank and allow it to cool to room temperature. After opening the tank, place a glass rod directly above the opening of the stainless steel aging tank, with the bottom of the glass rod at the same level as the opening of the stainless steel aging tank. Let it fall vertically and freely. When you hear the sound of the glass rod hitting the bottom of the tank, it means there is no hard sediment.

[0097] The thermal stability of the unblocking agent emulsions prepared in Examples 1-5 and Comparative Examples 1-2 were tested respectively, and the test results are shown in Table 2 below.

[0098] Table 2:

[0099]

[0100]

[0101] As can be seen from the test results in Table 2, the unblocking agent emulsions prepared in Examples 1-5 of this invention showed no hard precipitate after standing at 180°C for 16 hours, indicating good thermal stability. In contrast, the unblocking agent emulsions prepared in Comparative Examples 1-2 showed hard precipitate after standing at 180°C for 16 hours, indicating poor thermal stability.

[0102] Performance Evaluation 3 (Unlocking Performance of Unlocking Agent Emulsion)

[0103] The card-unlocking performance of the card-unlocking emulsion was tested. The test method was as follows:

[0104] (1) Preparation of base slurry: Add 350 mL of distilled water to a stainless steel high-speed stirring cup, add 0.12 g of sodium hexametaphosphate at 11000 r / min, and continue stirring for 5 minutes. Then, add 0.35 g of anhydrous sodium carbonate, 10 g of bentonite for drilling fluid test slurry preparation, 22 g of evaluation soil for drilling fluid test, 18 g of attapulgite (Changzhou Dingbang Mineral Products Technology Co., Ltd.), and 1 g of sulfonated tannin for drilling fluid (Chengdu Chuanfeng Chemical Engineering Co., Ltd.) every 5 minutes. Continue stirring for 5 minutes. Adjust the pH value to 9-10 with sodium hydroxide solution (20%). Add 140 g of barite powder (Sichuan Haiwo Petroleum Engineering Technology Co., Ltd.) at 11000 r / min and continue stirring for 20 minutes. This is the base slurry.

[0105] (2) Preparation of the unblocking agent emulsion: Take a stainless steel high-speed stirring cup, measure 233 mL of No. 0 diesel (Huayou Supply Department Beizhan Road Gas Station) with a measuring cylinder, add it to the stainless steel high-speed stirring cup, add 6 g of diesel-based organic clay (Tianjin Jinhaopeng Trading Co., Ltd.) at 11000 r / min, continue stirring for 5 minutes, add 40 mL of drilling fluid unblocking agent at 11000 r / min, continue stirring for 5 minutes, add 127 mL of distilled water at 11000 r / min, continue stirring for 10 minutes, add 140 g of barite powder (Sichuan Haiwo Petroleum Engineering Technology Co., Ltd.) at 11000 r / min, continue stirring for 20 minutes, the resulting liquid is the unblocking agent emulsion.

[0106] (3) Pour the base slurry prepared in (1) into the drilling fluid cup of the filter cake adhesion coefficient tester. Under a pressure of 690 kPa, after a filtration time of 30 minutes, an evaluation filter cake is formed. During the test, the adhesion plate in the drilling fluid cup is always kept in an upward state and does not contact the filter cake. Pour out the base slurry and pour in the unblocking agent emulsion prepared in (2). Under a pressure of 690 kPa, soak the filter cake for 30 minutes and pour out the liquid. Together with the drilling fluid cup of the filter cake adhesion coefficient tester, rinse the filter cake with a wet sieve under a pressure of 69 kPa. The nozzle of the wet sieve is close to the filter cake for rinsing until all the unblocking agent emulsion adhering to the surface of the filter cake is rinsed off. Immediately observe whether obvious network cracks appear on the surface of the filter cake.

[0107] The card-unblocking performance of the card-unblocking emulsions prepared in Examples 1-5 and Comparative Examples 1-2 was tested respectively, and the test results are shown in Table 3 below.

[0108] Table 3:

[0109]

[0110]

[0111] As can be seen from the test results in Table 3, the card-unlocking emulsions prepared in Examples 1-5 of this invention have good card-unlocking performance. The card-unlocking emulsions prepared in Comparative Examples 1-2 have poor card-unlocking performance.

[0112] Performance Evaluation 4 (Rheological properties, thermal stability, and card release performance of high-density card release agent emulsion)

[0113] The rheological properties, thermal stability, and card-unlocking performance of the high-density card-unlocking emulsion were tested.

[0114] Preparation method of high-density unblocking agent emulsion: Take one stainless steel high-speed stirring cup, measure 183mL of No. 0 diesel oil (Beizhan Road Gas Station, Huayou Supply Department) with a graduated cylinder, and add it to the stainless steel high-speed stirring cup. Add 40mL of drilling fluid unblocking agent at 11000r / min, and continue stirring for 5 minutes. Add 20mL of distilled water at 11000r / min, and continue stirring for 10 minutes. Add 690g of barite powder (Sichuan Haiwo Petroleum Engineering Technology Co., Ltd.) at 11000r / min, and continue stirring for 20 minutes. The resulting liquid has a density of 2.16g / cm³. 3 High-density card-unblocking emulsion.

[0115] Rheological property testing method: Prepare one sample with a density of 2.16 g / cm³. 3 The rheological properties of a high-density unblocking agent emulsion were tested at 50°C.

[0116] Thermal stability test method: A sample with a density of 2.16 g / cm³... 3 Pour the high-density unblocking agent emulsion into a stainless steel aging tank. After purging the tank with nitrogen for 30 seconds at 690 kPa pressure, place it vertically in a 180°C electric drying oven and let it stand at a constant temperature for 16 hours. Maintaining the vertical position throughout, remove the stainless steel aging tank and allow it to cool to room temperature. After opening the tank, place a glass rod directly above the opening of the aging tank, with the bottom of the rod at the same level as the opening. Let it fall vertically and freely. When you hear the sound of the glass rod hitting the bottom of the tank, it indicates that there is no hard sediment.

[0117] Test method for card release performance: Add 350mL of distilled water to a stainless steel high-speed stirring cup, add 0.12g of sodium hexametaphosphate at 11000r / min, and continue stirring for 5 minutes. Then, add 0.35g of anhydrous sodium carbonate, 10g of bentonite for drilling fluid test slurry preparation, 22g of evaluation soil for drilling fluid test, 18g of attapulgite (Changzhou Dingbang Mineral Products Technology Co., Ltd.), and 1g of sulfonated tannin for drilling fluid (Chengdu Chuanfeng Chemical Engineering Co., Ltd.) every 5 minutes, and continue stirring for 5 minutes. Adjust the pH value to 9-10 with sodium hydroxide solution (20%), add 140g of barite powder (Sichuan Haiwo Petroleum Engineering Technology Co., Ltd.) at 11000r / min, and continue stirring for 20 minutes. This is the base slurry. The base slurry was poured into the drilling fluid cup of the filter cake adhesion coefficient tester. Under a pressure of 690 kPa and a filtration time of 30 minutes, an evaluation filter cake was formed. During the test, the adhesion plate in the drilling fluid cup was kept in an elevated position and did not contact the filter cake. The base slurry was then poured out, and a density of 2.16 g / cm³ was added. 3 A high-density unblocking agent emulsion was used to soak the filter cake for 30 minutes at a pressure of 690 kPa, and the liquid was then poured out. The filter cake, along with the drilling fluid cup of the filter cake adhesion coefficient tester, was then rinsed with a wet sieve at a pressure of 69 kPa. The nozzle of the wet sieve was brought close to the filter cake for rinsing until all the unblocking agent emulsion adhering to the filter cake surface was washed away. Immediately afterward, the surface of the filter cake was observed for any obvious network cracks.

[0118] The unblocking agents prepared in Examples 1-5 and Comparative Examples 1-2 were formulated to a density of 2.16 g / cm³. 3 A high-density unblocking agent emulsion was prepared, and its rheological properties, thermal stability, and unblocking performance were tested. The test results are shown in Table 4 below.

[0119] Table 4:

[0120]

[0121] As can be seen from the test results in Table 4, the unblocking agent prepared by this invention can be formulated with a density of 2.16 g / cm³. 3 High-density card-unblocking emulsion. The density obtained in Examples 1-5 of this invention is 2.16 g / cm³. 3 The high-density unblocking agent emulsion exhibits significantly better rheological properties, thermal stability, and unblocking performance than Comparative Examples 1 and 2.

[0122] In the above embodiments, the rheological properties, thermal stability, and unblocking performance of the unblocking agent emulsions prepared in Examples 1-5 are significantly better than those in Comparative Examples 1 and 2. Therefore, the preferred reaction conditions are 35-48 parts of penetrant, 5-12 parts of stabilizer, 6-15 parts of flow modifier, 25-35 parts of emulsifier, and 2-10 parts of base oil. Furthermore, in these preferred embodiments, the unblocking agent emulsions of Examples 1-4 exhibit even better rheological properties; therefore, the preferred amount of penetrant is 35-45 parts. Furthermore, in these preferred embodiments, the unblocking agent emulsions of Examples 1-3 exhibit better thermal stability; therefore, the preferred amount of stabilizer is 5-10 parts.

[0123] The method for preparing the drilling fluid unblocking agent of the present invention includes the following steps:

[0124] (1) Take the penetrant and add it to the stabilizer, then mix them;

[0125] (2) Add the flow pattern regulator and mix;

[0126] (3) Add emulsifier and mix;

[0127] (4) Add base oil and mix.

[0128] The resulting composition is an unblocking agent for drilling fluids.

Claims

1. A drilling fluid unblocking agent, characterized in that, It includes the following components: 35-48 parts penetrant, 5-12 parts stabilizer, 6-15 parts flow pattern modifier, 25-35 parts emulsifier, and 2-10 parts base oil.

2. The drilling fluid unblocking agent according to claim 1, characterized in that, The amount of the penetrant is 35-45 parts.

3. The drilling fluid unblocking agent according to claim 1, characterized in that, The stabilizer is 5-10 parts.

4. The drilling fluid unblocking agent according to claim 3, characterized in that, The stabilizer is a diesel-based organic clay.

5. The drilling fluid unblocking agent according to claim 1, characterized in that, The penetrant is one or both of isooctanol polyoxyethylene ether and sodium fatty alcohol polyoxyethylene ether sulfate.

6. The drilling fluid unblocking agent according to claim 1, characterized in that, The flow pattern regulator is one or two of dodecyltrimethylammonium chloride and dihydroxyethyl laurylamine.

7. The drilling fluid unblocking agent according to claim 1, characterized in that, The emulsifier is one or both of sodium polyacrylate and sodium dodecyl sulfate.

8. The drilling fluid unblocking agent according to any one of claims 1-7, characterized in that, The base oil is one or both of No. 0 diesel oil and No. 5 white oil.

9. A method for preparing the unblocking agent for drilling fluid according to any one of claims 1-8, characterized in that, include: (1) Mix the penetrant and stabilizer; (2) Add the flow pattern regulator and mix; (3) Add emulsifier and mix; (4) Add base oil and mix.

10. The application of the drilling fluid unblocking agent according to any one of claims 1-8 in oil and gas field drilling.

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